Adding machine



M. M. MUNK 1,946,174 I ADDING MACHINE Feb. 6, 1934;v

Filed Aug. 13, 1932 l Fig.3. Figlr. Fig.5.

Patented Feb. 6, 1934 PATENT FFICE ADDING MACHINE Max M. Munk,Washington, D. 0.

Application August 13,

6' Claims.

This invention relates to improvements of adding or subtracting machinesof simple, sturdy, and preferably keyless construction. The objects ofthe improvements are to provide for such adding machine with a smallnumber of differing parts in which the setting and reading are speciallyfacilitated, and which is continuously operated, that means the transferfrom the digits of lower order to the digits of higher order is takencare of automatically and without special action of the computer.According to the invention these advantages are obtained by gearing toeach other continuously and resiliently equal and coaxial numbercylinders, by providing touch marks for the setting of these cylinders,and by providing multiple index marks for the reading of thesecylinders.

These and other desirable objects and advantages of the presentinvention will be illustrated in the accompanying drawing and describedin the specification, certain preferred embodiments being disclosed byWay of illustration only, for, since the underlying principles may beincorporated in other specific devices, it is not intended to be limitedto the ones here shown except as such limitations are clearly imposed bythe appended claims.

In the drawing like numerals refer to similar parts throughout theseveral views, of which Fig. 1 represents a side elevation of the addingmachine, of which in the center a portion of the casing is cut away toshow the inside in View, and at the left to show it in cross section,

Fig. 2 represents a cross section of the same adding machine on the lineI--I,

Fig. 3 is a cross section through a portion of the housing of a variedadding machine on the line II-II of Fig. 4,

Fig. 4 shows the front view of the same portion of the housing, and

Fig. 5 shows the cross section of a varied number cylinder.

The exterior of the adding machine comprises the cylindrical housing 1,with lids 2 on either end, held together by three rods 3, carrying eacha spacer 4 on the left side. Inside the housing are a plurality of equalcomputation units, comprising each a number cylinder 5, a gear cylinder6, a spacing disc 7, and a spring 8. Number cylinder 5 has insideflanges 9 and 10 on both ends. Flange 9 is plain and circular except forthe two straight and parallel portions 11. Flange 10 is indented toconsist of forty equal and equidistant gear teeth 12. Gear cylinder 6has an inside flange 13 on one end of which are punched 1932. Serial No.628,723

out three circular indentations 14 of a diameter larger than thediameter of rods 3. There are further punched and bent out of its mantletwelve equal equidistant radial projections 15. Spacing disc '7 is planeand circular and has three round holes punched out to fit the three rods3. Spring 8 is a spiral of line elastic wire, hung by its two ends tonumber cylinder 5 on two brackets 16 of flange 9, and stretching aroundhalf the circumference of the gear cylinder pulling the gear cylinder atone point of its circumference into mesh with the number cylinder,whereby the smaller gear cylinder is made to occupy an excentricposition relative to said larger number cylinder enclosing it and inmesh with it. The outside of the number cylinder is provided with fortyequidistant numbers, consecutively marked zero to nine, 17. They can beobserved through the windows 18 of the housing, one window for eachnumber cylinder. A multiple index mark 22, consisting of four individualindex marks, designated by zero, three, six, and nine, is provided onthe housing adjacent to each Window. There are further punched out ofthe housing setting slots 19, one for each number cylinder. Their widthis changing, so that two shoulders 20 are formed. Adjacent to thesetting slots are pro vided scales 21 designated one to nine, thedistance of consecutive numbers being one fortleth of the circumference.

Figs. 3 and 4 show as a variation a setting slot 19 of constant width.Corrugations 24 are substituted for the shoulders 20. Fig. 5 shows avariation of the number cylinder. A rubber band 25 is laid around thecircumference in a groove 26.

The last number cylinder 5" at the right of Fig. 1 serves merely asstructural part and as spacer. No window nor setting slot is providedfor it, and it is not rotatable, being fastened to the housing by thebolt and nut 23.

The kinematics of the computation units is as follows: When a tangentialforce is applied to a number cylinder through its setting slot, the gearcylinder in mesh with it is forced out of mesh towards the axis of thehousing, whereby the tension of the spring stretched around said gearcylinder is increased. Said first gear cylinder acts like a pawl, guidedby the shoulders 11 and kept from turning, but not from executing atranslational planetary gearing motion, by the rods 3. It moves radiallyat the point of mesh, and brings about that the number cylinder isturned by whole multiples of 9, this being the angular distance betweenadjacent gear teeth 12. 110

The number cylinder to the right is left in its position. While thenumber cylinder is turning, the gear cylinder in mesh with the adjacentnumber cylinder to the left, that is of next higher order, acts as agear wheel. It produces a true crawling transfer from a number ofcylinder of lower order to those of higher order, this transfer notbeing merely crawlingly accumulated in storage elements anddiscontinuously transmitted to the number cylinders as in manycalculation machines heretofore disclosed, but being inherentlycrawling, so that the number cylinders themselves perform the crawlingmotion. As a consequence, the result of the addition is shown in a trainof numerals 17 of number cylinders 5 arranged near a straight line, butnot exactly on a straight line. The point of mesh between projections 15of said second gear cylinder and of teeth 12 of said second numbercylinder rotates with the first number cylinder because the springstretched around said second gear cylinder and hence the direction ofits pull rotates that way. Teeth 12 and projections 15 act as the teethof a pair of gear wheels, and the driven number cylinder, which is theone of higher order, is rotated through one tenth of the angle ofrevolution of the driving number cylinder.

It will thus be seen that there has been provided a plurality of numberelements 5 continuously and resiliently geared with each other.

Continuous gearing means a gearing such that each number cylinder, thatis the element displaying the digits of the result, takes part itself ina continuous crawling transfer motion whenever a number cylinder oflower order is actuated. This involves that the digits displaying theresult are arranged near a straight line, but generally not exactlyalong a straight line. Resilient gearing means a gearing such that eachnumber cylinder can be turned by the operator independent of theelements 5 of lower order, whereby the gear connections between saidcylinder and said elements become temporarily ineffective, yieldelasiicaily, and uncouple under a turning force in excess of thatcapable of being transmitted through said gear connections.

The operation of the adding machine is as follows: Beginning at the leftside, turn all number cylinders through their setting slots until thefirs; number of those to be added together is indicated through thewindows 18. For each digit of each further summand, put a finger at thetop of the corresponding setting slot, and move the cylinder down up tothe corresponding index 21. The motion through each division can befelt, as each time a spring 8 is stretched. This in connection with thefeeling of the shoulders 20 makes it possible to set the cylinders bytouch. For adding four, for instance, move the finger first to the uppershoulder, and move by one additional step. When all summands are thatway applied, the sum is indicated through the windows 18. Each digitstands adjacent to that indication mark 22 in nearest agreement with thenumbers in the window of next lower order, that is directly to theright. In Fig. 1, for instance, the window to the right shows two.Hence, the adjacent window to the left gives the result near the indexthree, this one being closer to two than any other one.

I claim:

1. An, adding machine comprising a housing and a plurality of numbercylinders rotatably mounted in the housing, each pair of consecuvtivenumber cylinders being continuously and resiliently geared with eachother.

2.. An adding machine comprising a housing, a plurality of numbercylinders rotatably mounted in the housing and visible from outsidethrough windows in the; housing, and a multiple index mark adjacent tosuch window.

3. A keyless adding machine comprising a housing, aplurality of numbercylinders mounted in the housing and rotatable from outside throughsetting slots in the housing, and marks near thesetting slots on; thehousing adapted to be perceived by (touch, whereby the setting of thenumber cylinders-is guided.

4. A keyless adding machine comprising a housing, a plurality of numbercylinders mounted in the housing and rotatable from outside throughsetting slotsof variable width-in the.

housing, and resilient and continuous gearing means between. adjacentnumber cylinders.

5. In a keyless adding machine acomputation unit comprising a rotatablenumber cylinder and continuous resilient gearing means, the numbercylinder being surfacedwithhigh friction material. 1

6; An adding machine comprising a housing, a plurality of equalandcoaxial number cylinders rotatably mounted in the housing, aplurality of equal gear elements inside the numbercylinders, each gearelementtbeing in elastic connection with one number cylinder and adaptedto mesh continuouslywith the adjacent num ber cylinder of next higherorder, andmeans for keeping the gear elements from rotation.

MAX M. MUNK.

